The city is moving to rezone two brownstone-laden Brooklyn neighborhoods, the city’s planning commissioner announced Tuesday evening, part of an effort to harness growth in the city’s largest borough.

“There is tremendous confidence in the market, so that’s why we have been so active in rezoning,” Amanda Burden said at a real estate forum.

Zoning changes will be proposed for the southern half of Bedford-Stuyvesant and much of Fort Greene/Clinton Hill, the city’s planning director for Brooklyn, Purnima Kapur, said yesterday. The rezonings would combine the commission’s trademark caps on heights of side street buildings along with an allowance for taller buildings on commercial corridors in exchange for the inclusion of affordable units.

In addition to Ms. Burden, the annual event hosted by the Real Deal real estate publication brought together on stage four big names from the real estate community, including Stephen Ross of the powerhouse developer Related Companies and residential developer Kent Swig.

The panelists generally gave a strong vote of confidence to the city’s real estate market, brushing aside notions that a national housing slowdown would spill into New York.

“I think the market in New York has been good,” Mr. Ross said, adding that press reports regarding a possible slowdown have scared buyers and kept prices down.

While new condos are constantly shooting up throughout the city, the panelists held that an increasing population and increasing wealth in the city keep demand high, allowing New York to buck national trends.

“The marketplace on the super high luxury end, I don’t know where it ends, honestly,” Mr. Swig said.

The optimism of Messrs. Swig and Ross often drowned out the one voice on the panel expressing concerns of a slowdown, that of an economist at Yale University, Robert Shiller.

“I think there’s a tendency to focus on the short run,” Mr. Shiller said. With an unstable mortgage market, as seen in a recent rash of foreclosures, “I see the possibility of a national correction, and while New York is unique,” he added, “it could get carried along.”

Mr. Ross denounced the recent changes to the city’s 421-a program, which modified tax incentives for developers, tying them to affordable housing in parts of Manhattan and Brooklyn.

Even so, Mr. Ross offered strong support for the city’s efforts to create affordable housing, saying, “The one thing New York really needs is more workforce housing and affordable housing.”